Sheet mounting mechanism



July 28, 1936. w. G. H. FINCH SHEET MOUNTING MECHANISM Original Filed Feb. 26, 1936 IIIlIllI'lllllu llll M41 ATTORN Y.

Patented Jul 28, 1936 UNITED STATES.

PATENT OFFICE Divided and this application March 1a, 1936, Serial No. 69,596

' 8 Claims. (01. 178-13) v or continuous sheet type. In a drum system, the

record sheet is mounted upon a cylinder or drum for scanning at the transmitter and receiver stations. Various means have heretofore been employed for mounting the sheet upon the drum. The pictures to be transmitted were reduced or enlarged to the size necessary for mounting upon the particular size of picture drum.

I contemplate mounting picture sheets of different sizes upon a drum which has a plurality of novel film clamping means disposed along its length. Where large picture drums are used for correspondingly large picture sheets, difficulties are encountered in rapidly and smoothly mounting the picture sheets. I provide a novel presser roller mechanism for overcoming these difliculties in mounting large record sheets on large picture drums.

Accordingly, an object of my invention is to provide a novel picture drum and novel methods of mounting picture films thereon.

A further object of myinvention' is to provide novel clamping mechanisms for securing the picture to the drum.

Still a further object of my invention is to provide novel methods of and means for insuring a smooth, closely adhering application of the picture film to the drum.

Still a further object of my invention is to provide a novel picture drum which will directly indicate the size of the picture to be transmitted or apprise the operator of the length of the portion of a picture scanned.

. There are other objects of my invention together with the foregoing which will appear in the detailed description of my invention made in connection with the drawing, in which:

Figure 1 is a plan view of a preferred form of my novel drum;

Figure 2 is a cross-sectional view through 22 of Figure 1 of the picture drum showing details of my novel film clamping mechanism; and V Figure 3 is a partial perspective view of the film clamping mechanism.

Referring now specifically to the drawing, I disclose in this application which is a division of my application Serial No. 65,869 filed February 26, 1936, a pluralityof film clamp members It disposed along one section of the circumference of the picture drum 9 for engaging opposite ends of the picture sheet to be transmitted. Figure 2 is a cross-sectional illustration of the film clamp assembly l0 and the rollers II.

A picture sheet i2 is placed upon the picture drum 9 in the following manner: The coacting film clamps l3 and I4 have two portions l5 and I6 for clamping the corresponding opposite ends I! and i8 of the picture sheet l2; A cam 20 operates upon each film clamping assembly "I. 10 Tile cam members 20 are mounted on a common cam shaft 2| at one end of which is attached a lever 22. The coacting film clamps l3 and it are riveted together at the pivots 23. The ends 24 and 25 of the clamps l3 and II are elastically fastened by spring 26. The normal position of the clamps l3 and I4 is such that their toothed portions l5 and I6 grip against the surface plate 8 of the drum 9 or grip into the corresponding ends i1 and I8 of the picture sheet I2. It is to be understood that the clamping mechanism i0 illustrated in Figure 1 is duplicated in the plurality of clamping members H] which are employed along the picture drum as illustrated in Figure 1.

In order to insert one end I! of the record sheet l2 under the toothed portions l5 of the film clamp members Hi, the lever 22 is moved so that the cam 20 presses against the arm of the member [3. The toothed portion i 5 of clamp I3 is ac.-

cordingly raised from the drum surface 8 permitting the edge I! of the sheet l2 to be inserted thereunder. It is to be understood that this edge I! is inserted under corresponding toothed portions ii of clamping mechanisms Ill. The lever 22 is returned to its normal position and the clamp teeth l5 grip the sheet l2 firmly to the drum surface 8 along the sheet edge II.

The rollers II are moved into engagement with the drum 9 to firmly and evenly apply pressure upon the film l2 along the drum 9. The plurality of rollers II are illustrated pressing upon the drum in Figure 1. The dotted position 1 indicates the positionof the rollers it out of operative relation with the drum 9. The rollers are preferably solid metal cylinders, rotatably mounted on a common shaft 30. Collars 3| are used to separate them. A rubber or other suitable surfacing 32 is placed on the rollers II to protect the film or record sheet l2.

Figure 2 illustrates how the rollers, are used to facilitate proper mounting of record sheet l2 upon the drum l3 after one end I! of the sheet I 2 is ripped in positionby the clamp members l3. The rollers Ii are pressed down near the sheet end I! and the drum I3 is slowly rotated manually. The film I2 is accordingly firmly pressed in position around the drum iii. The opposite sheet end [8 is gripped under the teeth iii of clamp I4 by operation of the lever 22 and cam members 20 as will now be understood.

The film clamping arrangement according to my invention provides the gripping of any length of picture for transmission. The drum has a circumference of 11 inches, and in my preferred embodiment, is 17 inches long. Standard 10" by 14" pictures are readily accommodated on such a drum. The only size requirement is that one dimension of the sheet l2 should be such as to fit onto the drum 9 to be securely clamped in position by the clamping mechanism H), the rollers ll assisting in smoothly mounting the picture I2. I also provide a scale 40 which is marked along dead or underlap portion of the drum, namely that portion containing the clamping members it for the dead ends l'l-i8 of the picture sheet l2. Small circumferential grooves H are made in the surface 9 of the drum 8 corresponding to integral marked spacings of the scale 40. The distance between these grooves or scale markings H is preferably one inch. The operator is readily apprised of the size of a picture mounted for transmission, or of the length of a portion picture already scanned during its transmission.

Although in connection with my novel clamping mechanisms I may employ any desired drive connection and support for the drum I have for the purpose of illustration here illustrated the mounting of the drum as shown in the parent application Serial No. 65,869 supra. Rotative power is supplied to the spindle 49 extending from a suitable drive connection (not shown) in any well known manner. Rigidly connected and rotatable with the spindle 49 is a face plate driver 50. A key or projection 51 on the face of the driver 50 sets into a corresponding groove into flange 52 of the receiver drum 9. The opposite end of the drum 9 is provided with a flange 53 which contains the corresponding end of the drum shaft 54. A supporting member 55 contains conical or pointed spindle 56 which projects into a cavity in the shaft 54 end. The drum is accordingly rotatably supported and driven by the shaft 49.

It is to be understood that the sheet mount ing mechanism may be used in connection with a telepicture transmitter or receiver. In a transmitter, a beam of light is focused upon a picture sheet mounted on the drum. The drum is rotated at a constant rate, while the scanning mechanism moves along the drum parallel to its axis. The light beam is refracted from the picture sheet to impinge upon a photoelectric cell for producing corresponding telepicture signals. In a receiver, a light sensitive film is mounted upon the drum and a light beam with intensity varying in accordance with the received telepicture signals is scanned across the sensitive film to reproduce the transmitted picture thereon.

Although for the purpose of illustration I have shown preferred forms of my invention it will be obvious to those skilled in the art that it may take other forms, and I do not intend to be limited except as set forth in the appended claims.

I claim:

1. A sheet mounting mechanism comprising a drum; :3. pair of clamps, each having a portion. protruding through a slot in said drum, said portion including a toothed section extending over said drum; means for rocking one of said clamps for lifting the toothed portion thereof from engagement with said drum to permit insertion of one edge of the sheet to be mounted on said drum; means for rocking the other of said clamps for lifting the toothed portion thereof from engagement with said drum to permit insertion of the other edge of the sheet to be mounted on said drum; said means comprising a cam surface; a rod carrying said cam; and a lever connected to said rod.

2. A sheet mounting mechanism comprising a drum; a pair of clamps, each having a portion protruding through a slot in said drum, said portion including a toothed section extending over said drum; means for mechanically biassing the opposite ends of said clamps toward each other and the toothed portions into engagement with said drum; means for rocking one of said clamps for lifting the toothed portion thereof from engagement with said drum to permit insertion of one edge of the sheet to be mounted on said drum; and means for rocking the other of said clamps for lifting the toothed portion thereof from engagement with said drum to permit inser tion of the other edge of the sheet to be mounted on said drum.

3. A sheet mounting mechanism comprising a drum; a plurality of clamps arranged in pairs, each having a portion protruding through a slot in said drum, said portion including a toothed section extending over said drum; and means for rocking corresponding clamps of each pair for lifting the toothed portions thereof from engagement with said drum to permit insertion of the edges of the sheet to be mounted on said drum.

4. A sheet mounting mechanism comprising a drum; a plurality of clamps arranged in pairs, each having a portion protruding through a slot in said drum, said portion including a toothed section extending over said drum; means for simultaneously rocking corresponding clamps of each pair for lifting the toothed portions thereof from engagement with said drum to permit insertion of the edges of the sheet to be mounted on said drum, said means comprising a cam surface; a rod carrying said cam; and a lever connected to said rod.

5. A sheet mounting mechanism comprising a drum; a plurality of clamps arranged in pairs, each having a portion protruding through a slot in said drum, said portion including a toothed section extending over said drum, the toothed portions of each pair being oppositely disposed with respect to each other; and means for mechanically biassing the opposite ends of said clamps toward each other and the toothed portions into engagement with the drum.

6. A sheet mounting mechanism comprising a drum; a plurality of clamps arranged in pairs, each having a portion'protruding through a slot in said drum transversely of the drum axis, said portion including a toothed section extending over said drum, the toothed portions of each pair being oppositely disposed with respect to each other; and means for mechanically biassing the opposite ends of said clamps toward each other and the toothed portions into engagement with the drum.

7. A sheet mounting mechanism comprising with respect to each other; a common pivot for each of said pairs of clamps; and means for mechanically blessing the opposite ends of said clamps toward each other and the toothed portions into engagement with the drum.

8. A sheet mounting mechanism comprising a drum; a plurality of clamps arranged in pairs, each having a portion protruding through a slot in said drum, said portion including a toothed ends.

section extending over said drum, the toothed portions of each pair being oppositely disposed with respect to each other; and a. spring for mechanically biassing the opposite ends of said clamps toward each other and the toothed portions into engagement with the drum, the opposite ends of said spring being secured to said WILLIAM G. H. FINCH. 

